INVESTIGATIONS IN GERMANY
BY
TANK ARMAMENT RESEARCH,
MINISTRY OF SUPPLY

SECTION E METHODS OF IMPROVING OBSERVATION OF FALL OF SHOT

NOTE: this section covers methods or reducing flash, smoke and dust which are produced when a gun is fired. It is desirable to reduce these factors both in order to improve the tank gunner's observation of fall of shot and also to avoid giving away the position to the enemy.

Rheinmetall-Borsig. Unterluss

Very little consideration has been given to this problem, although fairly recently a conical attachment fitted with internal cooling fins has been successfully developed for preventing flash from a 7.92m. rifle or machine gun. It had been intended to extend this design to larger calibres. A report, entitled "Flash suppresser", briefly describing this attachment was taken away.

Krupp. Essen

Dip.Ing. Theermann was chiefly concerned with gun design, but also designed Muzzle-brakes. Efforts to design muzzle attachments for reducing flash and blast pressure (and hence the amount of dust raised) were not very successful. It was realised that if the blast could be directed backwards the dust raised would interfere the least with the view of the tank gunner. On the other hand, it was found not possible to direct the blast backwards through more than about 105 deg to the line of fire on account of danger to unprotected personnel, such as supporting infantry. A report by Theermann on this work has been received.

Krupp, Essen (personnel evacuated to Kettwig)

Dr. Muller said that the Waffenkommission attached considerable importance to the search for methods of reducing flash, smoke and dust. Early in the war, German tank ammunition was flashing, but there was a swing over to flashless ammunition produced by introducing potassium sulphate into the propellant. At first a fairly satisfactory combination was obtained, though flashlessness was thus achieved at the expense of some smoke. Towards the end of the war, propellants deteriorated badly in quality and smoke became excessive. At this stage, users said they would prefer flashing to flashless ammunition. No advantage was gained by using electric primers.
Contrary to certain reports, no change over from flashing to smoking ammunition was made for tanks in poor and fading light.

Experiments were done to determine the optimum port size for muzzle-brakes, and it was considered that those for the Pak 7.5 cm. were about right.

{ NOTE: T.A.R. experiments have shown that when the Pak 7.5 cm. muzzle-brake is attached to the 17-pr. gun in Challenger, the amount of forward dust raised is slightly less than with the British service muzzle-brake.}

Rheinmetall-Borsig, Dusseldorf

Propellants deteriorated as the war progressed and smoke was becoming a real nuisance. Tanks were therefore just being provided with long periscopes 1½ metres), which were stated to be quite satisfactory (but compare with statement by General Guderian - see below).

All tank guns were fitted with muzzle brakes, but the recoil systems were designed to stand recoil in the absence of muzzle-brakes. The effect of blast on the tank crew was always a factor considered in designing muzzle-brakes. The effect of muzzle-brakes on flash, dust and smoke was not considered. (This is at variance with statement by Krupp personnel).

Flash was considered less important as an obscuring element than smoke, even at dusk, because of its momentary duration. In any case the commander could use his long periscope.

Schmiedag Fabrik (between Rummenohl and Evringshausen)

This factory making muzzle-brakes was evacuated in January 1943 from the firm's main works at Hagen. A fairly large stock was in store. Arrangements were made to have two of each of all types made evacuated to T.A.R. They are for the following guns:-

7.5cm

Pak 40 )

Same design of brake, but two
different methods of construction.

" "

KwK 40)

" "

StuH 4 0)

" "

Pak 40 M

8.8"

Pak 43

10.5"

le F.H.18

10.5"

le F.H.l8/40

Brakes of the cylindrical multi-perforated type (12.8 cm. and 17.0 cm. guns), although possessing rather low braking efficiency, were designed for ease of production and not for reducing dust raised by blast. In fact it was not thought that any tests had been made to investigate any possible effect in this respect. They were considered to minimise the blast effect on the crew.

Armaturen Fabrik, Bernard Brender, Grevenbruck

Various types or muzzle-brakes had been manufactured. They were similar in general design to those found at Schmiedag Fabrik,

Krupp's Main Range Meppen

A large number of experimental muzzle-brakes for guns up to 20.3 cm. calibre were seen, Some were of most unusual design, but with the evidence of Theermann in mind they were considered of no interest from the point of view of reduction of flash and dust. (C.E.A.D. has seen this selection of brakes, and considers them of no interest - C.I.O.S., Evaluation Report No.29).